Studies on insecticide use pattern, population susceptibility and insecticide evaluation against Amrasca biguttula biguttula (Ishida) in cotton
Loading...
Date
2020-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU, Hisar
Abstract
A survey was carried out to study the insecticide use pattern in Sirsa, Hisar and Bhiwani districts of Haryana during kharif, 2019. The maximum respondents (70.00%) were found to be belonging to the age group of 40-60 years. Education status of farmers was quite good with an overall literacy rate of 87.00% and 56.00% of the respondents were having more than 15 years of experience in cotton cultivation. Most commonly grown Bt cotton hybrid by the majority of farmers (34%) was RCH 773 BG II followed by RCH 776 BG II (31.30%), US 51 BG II (13.30%), Ankur 3028 BG II (13.30%) and US 81 BG II (8.00%). Based on farmers experience, whitefly, Bemisia tabaci and leafhopper, Amrasca biguttula biguttula were the most important pests among sucking pests in Bt cotton. All the farmers were found to target whitefly and leafhopper for control whereas in case of dusky cotton and red cotton bug none was reported to targeting for control. The incidence, severity and yield losses of sucking pests especially whitefly and leafhopper were estimated to be high by 100, 86.67 & 82.70; 76.67, 74.00 & 64.67% farmers, respectively. The cent per cent farmers was found to adopt control measures at 61-90 days after sowing as highest pest incidence was estimated by cent per cent farmers at this duration. The majority of the farmers (44.67%) were found to be dependant on Agriculture input dealers for information in cotton cultivation followed by CCS HAU Hisar/CICR-RS (34.66%). Major constraints faced by farmers in insect pest management were high cost of pesticides, weather problems and lack of knowledge about bioagent and insubstantial control or poor efficacy of insecticides. Insecticides like imidacloprid, thiamethoxam, emamectin benzoate, fipronil, dimethoate and monocrotophos were mainly used by farmers to control sucking pests. Besides, newer insecticides like flonicamid, dinotefuran, diafenthiuron, spiromesifen and spinetoram were also being used by farmers. Insecticide-bioassays were carried out to assess the susceptibility of field-collected cotton leafhopper from Hisar, Sirsa and Bhiwani districts to commercial formulations of imidacloprid 17.8% SL, thiamethoxam 25% WG and flonicamid 50% WG during kharif, 2019. Intrinsic toxicity data on imidacloprid 17.8% SL, thiamethoxam 25% WG and flonicamid 50% WG indicated that Bhiwani population was most susceptible to these insecticides with LC50 values ranging from 7.23-24.74 ppm followed by Hisar population (10.09-29.83 ppm) whereas Sirsa population was found to be least susceptible with LC50 values of 12.17-34.60 ppm. Among different insecticides, flonicamid 50% WG with LC50 values ranging from 7.23 to 12.17 ppm showed maximum toxicity followed by thiamethoxam 25% WG 20.73 to 29.60 ppm while imidacloprid 17.8% SL was found to be least toxic insecticide with LC50 ranging from 24.74 to 34.60 ppm. Based on mean of two sprays in a field trial during kharif, 2019, the lowest mean nymhal and adults population (No. per 3 leaves) were recorded in flonicamid 50% WG @ 150 g ha-1 (0.84 nymphs and 1.73 adults) followed by dinotefuran 20% SG @ 150 g ha-1 (1.49 nymphs and 2.06 adults) and diafenthiuron 50% WP @ 500 g ha-1 (1.65 nymphs and 2.25 adults). Imidacloprid 17.8% SL @ 100 ml ha-1, thiacloprid 21.7% SC @ 125 ml ha-1, thiamethoxam 25% WG @ 100 g ha-1 and buprofezin 25% SC @ 1000 ml ha-1 were found to be moderately effective insecticides. Monocrotophos 36% SL @ 437 ml ha-1 was found to be the least effective insecticide. The non-significant differences were observed in the population of natural enemies (spiders, coccinellids & Chysoperla) among the different treatments. The highest seed cotton yield (q ha-1) was obtained with flonicamid (21.60), followed by dinotefuran (20.99), diafenthiuron (20.71), imidacloprid (20.41), thiacloprid (20.12), buprofezin (19.87), thiamethoxam (19.83) and monocrotophos (19.37). On the basis of cost of protection, the incremental cost benefit ratio was maximum with imidacloprid (1:6.36) followed by thiacloprid (1:5.64), thiamethoxam (1:5.29), monocrotophos (1:4.74), dinotefuran (1:4.38), flonicamid (1:3.99) and buprofezin (1:3.86).